The development of speech during the first three years of life is being chartered by means of acoustic measurements. Formant frequency patterns, spectrums, and voice onset data are measured by means of Sound Spectrograms and computer-implemented Fourier and Linear Predictive analysis. Initial data derived from six children and their parents show that adults provide special "well-formed" speech signals when they address children. These special signals would provide exemplars to the children that would aid in the acquisition of speech. There thus may be an interactive component involved in speech acquisition. The "innate" mechanisms for language acquisition may involve special behavior on the part of adults. Initial data on the formant frequencies of the children's vowels, however, show that they are not simply mimicking the acoustic parameters of the speech signals provided by their parents. The children's versions of the vowels of English have high formant frequencies consistent with the small lengths of their vocal tracts. They do not seem to be trying to imitate the lower formant frequencies of their parent's vowels. These data are consistent with the presence of an innately determined species-specific vocal tract normalizing "mechanism" that must be involved in speech perception.